IB/ehca: Remove unnecessary memory operations for userspace queue pairs

The queue map for flush completion circumvention is only used for
kernel space queue pairs.  This patch skips the allocation of the
queue maps in case the QP is created for userspace.  In addition, this
patch does not iomap the galpas for kernel usage if the queue pair is
only used in userspace.  These changes will improve the performance of
creation of userspace queue pairs.

Signed-off-by: Stefan Roscher <stefan.roscher@de.ibm.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 53 insertions, 41 deletions

diff --git a/drivers/infiniband/hw/ehca/ehca_qp.c b/drivers/infiniband/hw/ehca/ehca_qp.c
index 00c108159714..ead4e718c082 100644
--- a/drivers/infiniband/hw/ehca/ehca_qp.c
+++ b/drivers/infiniband/hw/ehca/ehca_qp.c
@@ -461,7 +461,7 @@ static struct ehca_qp *internal_create_qp(
 					      ib_device);
 	struct ib_ucontext *context = NULL;
 	u64 h_ret;
-	int is_llqp = 0, has_srq = 0;
+	int is_llqp = 0, has_srq = 0, is_user = 0;
 	int qp_type, max_send_sge, max_recv_sge, ret;
 
 	/* h_call's out parameters */
@@ -609,9 +609,6 @@ static struct ehca_qp *internal_create_qp(
 		}
 	}
 
-	if (pd->uobject && udata)
-		context = pd->uobject->context;
-
 	my_qp = kmem_cache_zalloc(qp_cache, GFP_KERNEL);
 	if (!my_qp) {
 		ehca_err(pd->device, "pd=%p not enough memory to alloc qp", pd);
@@ -619,6 +616,11 @@ static struct ehca_qp *internal_create_qp(
 		return ERR_PTR(-ENOMEM);
 	}
 
+	if (pd->uobject && udata) {
+		is_user = 1;
+		context = pd->uobject->context;
+	}
+
 	atomic_set(&my_qp->nr_events, 0);
 	init_waitqueue_head(&my_qp->wait_completion);
 	spin_lock_init(&my_qp->spinlock_s);
@@ -707,7 +709,7 @@ static struct ehca_qp *internal_create_qp(
 			(parms.squeue.is_small || parms.rqueue.is_small);
 	}
 
-	h_ret = hipz_h_alloc_resource_qp(shca->ipz_hca_handle, &parms);
+	h_ret = hipz_h_alloc_resource_qp(shca->ipz_hca_handle, &parms, is_user);
 	if (h_ret != H_SUCCESS) {
 		ehca_err(pd->device, "h_alloc_resource_qp() failed h_ret=%lli",
 			 h_ret);
@@ -769,18 +771,20 @@ static struct ehca_qp *internal_create_qp(
 			goto create_qp_exit2;
 		}
 
-		my_qp->sq_map.entries = my_qp->ipz_squeue.queue_length /
-			 my_qp->ipz_squeue.qe_size;
-		my_qp->sq_map.map = vmalloc(my_qp->sq_map.entries *
-					sizeof(struct ehca_qmap_entry));
-		if (!my_qp->sq_map.map) {
-			ehca_err(pd->device, "Couldn't allocate squeue "
-				 "map ret=%i", ret);
-			goto create_qp_exit3;
+		if (!is_user) {
+			my_qp->sq_map.entries = my_qp->ipz_squeue.queue_length /
+				my_qp->ipz_squeue.qe_size;
+			my_qp->sq_map.map = vmalloc(my_qp->sq_map.entries *
+						    sizeof(struct ehca_qmap_entry));
+			if (!my_qp->sq_map.map) {
+				ehca_err(pd->device, "Couldn't allocate squeue "
+					 "map ret=%i", ret);
+				goto create_qp_exit3;
+			}
+			INIT_LIST_HEAD(&my_qp->sq_err_node);
+			/* to avoid the generation of bogus flush CQEs */
+			reset_queue_map(&my_qp->sq_map);
 		}
-		INIT_LIST_HEAD(&my_qp->sq_err_node);
-		/* to avoid the generation of bogus flush CQEs */
-		reset_queue_map(&my_qp->sq_map);
 	}
 
 	if (HAS_RQ(my_qp)) {
@@ -792,20 +796,21 @@ static struct ehca_qp *internal_create_qp(
 				 "and pages ret=%i", ret);
 			goto create_qp_exit4;
 		}
-
-		my_qp->rq_map.entries = my_qp->ipz_rqueue.queue_length /
-			my_qp->ipz_rqueue.qe_size;
-		my_qp->rq_map.map = vmalloc(my_qp->rq_map.entries *
-				sizeof(struct ehca_qmap_entry));
-		if (!my_qp->rq_map.map) {
-			ehca_err(pd->device, "Couldn't allocate squeue "
-					"map ret=%i", ret);
-			goto create_qp_exit5;
+		if (!is_user) {
+			my_qp->rq_map.entries = my_qp->ipz_rqueue.queue_length /
+				my_qp->ipz_rqueue.qe_size;
+			my_qp->rq_map.map = vmalloc(my_qp->rq_map.entries *
+						    sizeof(struct ehca_qmap_entry));
+			if (!my_qp->rq_map.map) {
+				ehca_err(pd->device, "Couldn't allocate squeue "
+					 "map ret=%i", ret);
+				goto create_qp_exit5;
+			}
+			INIT_LIST_HEAD(&my_qp->rq_err_node);
+			/* to avoid the generation of bogus flush CQEs */
+			reset_queue_map(&my_qp->rq_map);
 		}
-		INIT_LIST_HEAD(&my_qp->rq_err_node);
-		/* to avoid the generation of bogus flush CQEs */
-		reset_queue_map(&my_qp->rq_map);
-	} else if (init_attr->srq) {
+	} else if (init_attr->srq && !is_user) {
 		/* this is a base QP, use the queue map of the SRQ */
 		my_qp->rq_map = my_srq->rq_map;
 		INIT_LIST_HEAD(&my_qp->rq_err_node);
@@ -918,7 +923,7 @@ create_qp_exit7:
 	kfree(my_qp->mod_qp_parm);
 
 create_qp_exit6:
-	if (HAS_RQ(my_qp))
+	if (HAS_RQ(my_qp) && !is_user)
 		vfree(my_qp->rq_map.map);
 
 create_qp_exit5:
@@ -926,7 +931,7 @@ create_qp_exit5:
 		ipz_queue_dtor(my_pd, &my_qp->ipz_rqueue);
 
 create_qp_exit4:
-	if (HAS_SQ(my_qp))
+	if (HAS_SQ(my_qp) && !is_user)
 		vfree(my_qp->sq_map.map);
 
 create_qp_exit3:
@@ -1244,6 +1249,7 @@ static int internal_modify_qp(struct ib_qp *ibqp,
 	u64 update_mask;
 	u64 h_ret;
 	int bad_wqe_cnt = 0;
+	int is_user = 0;
 	int squeue_locked = 0;
 	unsigned long flags = 0;
 
@@ -1266,6 +1272,8 @@ static int internal_modify_qp(struct ib_qp *ibqp,
 		ret = ehca2ib_return_code(h_ret);
 		goto modify_qp_exit1;
 	}
+	if (ibqp->uobject)
+		is_user = 1;
 
 	qp_cur_state = ehca2ib_qp_state(mqpcb->qp_state);
 
@@ -1728,7 +1736,8 @@ static int internal_modify_qp(struct ib_qp *ibqp,
 			goto modify_qp_exit2;
 		}
 	}
-	if ((qp_new_state == IB_QPS_ERR) && (qp_cur_state != IB_QPS_ERR)) {
+	if ((qp_new_state == IB_QPS_ERR) && (qp_cur_state != IB_QPS_ERR)
+	    && !is_user) {
 		ret = check_for_left_cqes(my_qp, shca);
 		if (ret)
 			goto modify_qp_exit2;
@@ -1738,16 +1747,17 @@ static int internal_modify_qp(struct ib_qp *ibqp,
 		ipz_qeit_reset(&my_qp->ipz_rqueue);
 		ipz_qeit_reset(&my_qp->ipz_squeue);
 
-		if (qp_cur_state == IB_QPS_ERR) {
+		if (qp_cur_state == IB_QPS_ERR && !is_user) {
 			del_from_err_list(my_qp->send_cq, &my_qp->sq_err_node);
 
 			if (HAS_RQ(my_qp))
 				del_from_err_list(my_qp->recv_cq,
 						  &my_qp->rq_err_node);
 		}
-		reset_queue_map(&my_qp->sq_map);
+		if (!is_user)
+			reset_queue_map(&my_qp->sq_map);
 
-		if (HAS_RQ(my_qp))
+		if (HAS_RQ(my_qp) && !is_user)
 			reset_queue_map(&my_qp->rq_map);
 	}
 
@@ -2138,10 +2148,12 @@ static int internal_destroy_qp(struct ib_device *dev, struct ehca_qp *my_qp,
 	int ret;
 	u64 h_ret;
 	u8 port_num;
+	int is_user = 0;
 	enum ib_qp_type	qp_type;
 	unsigned long flags;
 
 	if (uobject) {
+		is_user = 1;
 		if (my_qp->mm_count_galpa ||
 		    my_qp->mm_count_rqueue || my_qp->mm_count_squeue) {
 			ehca_err(dev, "Resources still referenced in "
@@ -2168,10 +2180,10 @@ static int internal_destroy_qp(struct ib_device *dev, struct ehca_qp *my_qp,
 	 * SRQs will never get into an error list and do not have a recv_cq,
 	 * so we need to skip them here.
 	 */
-	if (HAS_RQ(my_qp) && !IS_SRQ(my_qp))
+	if (HAS_RQ(my_qp) && !IS_SRQ(my_qp) && !is_user)
 		del_from_err_list(my_qp->recv_cq, &my_qp->rq_err_node);
 
-	if (HAS_SQ(my_qp))
+	if (HAS_SQ(my_qp) && !is_user)
 		del_from_err_list(my_qp->send_cq, &my_qp->sq_err_node);
 
 	/* now wait until all pending events have completed */
@@ -2209,13 +2221,13 @@ static int internal_destroy_qp(struct ib_device *dev, struct ehca_qp *my_qp,
 
 	if (HAS_RQ(my_qp)) {
 		ipz_queue_dtor(my_pd, &my_qp->ipz_rqueue);
-
-		vfree(my_qp->rq_map.map);
+		if (!is_user)
+			vfree(my_qp->rq_map.map);
 	}
 	if (HAS_SQ(my_qp)) {
 		ipz_queue_dtor(my_pd, &my_qp->ipz_squeue);
-
-		vfree(my_qp->sq_map.map);
+		if (!is_user)
+			vfree(my_qp->sq_map.map);
 	}
 	kmem_cache_free(qp_cache, my_qp);
 	atomic_dec(&shca->num_qps);